Gasket ring

ABSTRACT

The invention relates to a metal gasket ring ( 16 ) comprising an annular holder part ( 16   a ) and an annular resilient part ( 16   b ). The holder part ( 16   a ) forms a support surface for the resilient part ( 16   b ). A peripheral edge section ( 17 ) of the holder part ( 16   a ) is bent so that it overlaps the outer edge of the resilient part. The resilient part ( 16   b ) is provided with a bead ( 20 ), which projects outwards beyond the edge section ( 17 ) of the holder part, radially inside said edge section ( 17 ).

TECHNICAL FIELD

The present invention relates to a metal gasket ring, comprising anannular holder part and an annular resilient part.

BACKGROUND OF THE INVENTION

Sealing problems can occur in the case of assemblies subject to high gaspressures and temperature fluctuations. Such is the case when fixinginjectors into the cylinder head of a diesel engine. An injector isusually fitted into a space in the cylinder head cooled by coolant bymeans of a copper sleeve, which is flanged at the bottom and sealed atthe top by an O-ring. A screw connection presses the spray part againstthe flanged section of the sleeve, which is usually provided with adeformable bead for achieving the requisite sealing up against thecylinder head wall. Gas leakage can nevertheless occur at the contactface between the end of the injector and the flanged section of thesleeve. A leak often occurs after replacing the injector. One cause ofthis problem may be that the inlet side of the cylinder head is coolerthan the exhaust side, so that the flange section bead becomes unevenlydeformed. If leakage occurs, this can lead to resulting problemsoccurring, with damage to the cylinder head and costly operatinginterruptions.

The leakage problem described above can be avoided by changing thecopper sleeve at the same time as the injector. This means, however,that the coolant has to be drained off from the cylinder head, whichtogether with the material cost of the sleeve entails substantiallyincreased costs for this servicing operation.

It would be desirable to be able to change injectors in an enginewithout the risk of leakage and without changing the copper sleeve.

SUMMARY OF THE INVENTION

An object of the invention is therefore to produce a gasket ring whichwill withstand an environment with large temperature fluctuations anduneven pressure load, and which will allow injectors in an engine to bechanged without the risk of leakage and without changing the coppersleeve.

According to the invention a metal gasket ring for this purposecomprises an annular holder part and an annular resilient part and ischaracterized in that the holder part forms a support surface for theresilient part, that a peripheral edge section of the holder part isbent so that it overlaps the outer edge of the resilient part, and thatthe resilient part is provided with a bead, which projects outwardsbeyond the edge section of the holder part, radially inside said edgesection. This embodiment of the gasket ring according to the inventionmakes it possible to produce a resilient sealing joint between theinjector and the copper sleeve, which will withstand an uneven pressureload and large temperature fluctuations.

In one exemplary embodiment of the invention the holder part may be madefrom a material that is easier to form than the material from which theresilient part is manufactured. This facilitates forming of thecomposite gasket ring.

In another exemplary embodiment of the invention the holder part may beprovided with a number of indentations along the outer edge. Theindentations make it easier to bend the edge of the holder part aroundthe edge of the resilient part when forming the composite gasket ring.

In a further exemplary embodiment of the invention the holder part maybe provided with a number of tongues oriented radially inwards towardsthe center of a central opening. This is a simple way of providing meansfor fixing the gasket ring around the injector spray tip, which makes iteasier to fit the injector with gasket ring in the injector sleeve.

According to an advantageous variant of the invention the gasket ring inits position of use is fitted in a cylinder head, as seal between aninjector and an injector sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail below with reference toexemplary embodiments, which are shown in the drawings attached, inwhich

FIG. 1 in a schematic sectional side view shows a cylinder head withinjector and a gasket ring according to the invention,

FIG. 2 shows the gasket ring in plan view on a larger scale, and

FIG. 3 is a section along the line in FIG. 2.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The cylinder head 10, shown in FIG. 1, forming part of a diesel engine,is provided with side walls 10 a and 10 b, outer wall 10 c and cylinderhead wall 10 d, which together define an internal cavity 11 for coolant.The outer wall 10 c is provided with a cylindrical bushing for aninjector 13, which with its spray tip 13 a projects via a passagethrough the cylinder head wall 10 d into the combustion chamber (notshown). An injector sleeve 14 extends between the outer wall 10 c andthe inside of the cylinder head wall 10 d, and is provided with anO-ring seal 14 a inside the bushing 12 and a flanged section 14 b at thecontact face with the cylinder head wall 10 d. The injector 13 is fittedby means of a clamped union 15 comprising a bolt 15 a and a clampingshoe 15 b, in such a way that the injector presses with a predefinedforce against the cylinder head wall 10 d. A gasket ring 16 is arrangedbetween a shoulder section 13 b of the injector and the flanged section14 b of the sleeve 14.

The gasket ring 16 is shown in plan view on a larger scale in FIG. 2 andis made of metal, comprising an annular holder part 16 a and an annularresilient part 16 b. The function of the holder part 16 a is to form asupport surface for and to center the resilient part 16 b. For thispurpose a peripheral edge section 17 of the holder part 16 a is bentaround the outer edge of the resilient part 16 b, so that the edgesection partially overlaps the latter. In addition, the holder part 16 ais provided with a number of tongues 19, which are oriented radiallyinwards towards the center of a central opening 18 and which aredesigned to grip around the spray tip 13 a and to center the holder partin relation thereto. A further function of the tongues 19 is to hold thegasket ring 16 fast around the spray tip during fitting, which makes iteasier to fit the injector with gasket ring in the injector sleeve.

The resilient part 16 b is provided with an annular bead 20 radiallyinside the edge section 17 of the holder part, the bead 20 beingdimensioned so that it projects outwards at right angles from the planeof the gasket ring 16 beyond the edge section of the holder part.

Because the gasket ring 16 comprises two separate parts, metal ofdifferent characteristics can be used in these parts. Thus, for theholder part 16 a it is possible to use a material that is easier to formthan the material from which the resilient part 16 b is manufactured. Atthe same time a material having elastic characteristics can be used forthe resilient part 16 b. A number of indentations 17 a in the edgesection 17 of the holder part are designed to make it easier to bend theedge of the holder part around the edge of the resilient part whenforming the composite gasket ring.

Because the edge section 17 of the holder part 16 a prevents compressionof the bead, the latter can retain its elastic characteristics within afavorable interval, even though the bead is pressed down so far that theshoulder section of the injector rests against the edge section 17. Thismeans that the seal will be maintained even if the pressure load isuneven.

The invention must not be regarded as being limited to the exemplaryembodiments described above, a number of further variants andmodifications being feasible without departing from the scope of thefollowing patent claims. For example, the indentations 17 a of the edgesection 17 are not essential to the functioning of the gasket ring. Theresilient part may furthermore be provided with more than one annularbead.

1. A metal gasket ring comprising an annular holder part and an annularresilient part, wherein the holder part forms a support surface for theresilient part, that a peripheral edge section of the holder part isbent so that it overlaps the outer edge of the resilient part, and thatthe resilient part is provided with a bead, which projects outwardsbeyond the edge section of the holder part, radially inside the edgesection.
 2. The gasket ring as claimed in claim 1, wherein the holderpart is made from a material that is easier to form than the materialfrom which the resilient part is manufactured.
 3. The gasket ring asclaimed in claim 1, wherein the holder part is provided with a number ofindentations along the outer edge of the edge section.
 4. The gasketring as claimed in claim 1, wherein the holder part is provided with anumber of tongues oriented radially inwards towards the center of acentral opening.
 5. The gasket ring as claimed in claim 1, wherein inits position of use it is fitted in a cylinder head, as seal between aninjector and an injector sleeve.
 6. The gasket ring as claimed in claim2, wherein the holder part is provided with a number of indentationsalong the outer edge of the edge section.
 7. The gasket ring as claimedin claim 2, wherein the holder part is provided with a number of tonguesoriented radially inwards towards the center of a central opening. 8.The gasket ring as claimed in claim 2, wherein in its position of use itis fitted in a cylinder head, as seal between an injector and aninjector sleeve.
 9. The gasket ring as claimed in claim 3, wherein theholder part is provided with a number of tongues oriented radiallyinwards towards the center of a central opening.
 10. The gasket ring asclaimed in claim 3, wherein in its position of use it is fitted in acylinder head, as seal between an injector and an injector sleeve. 11.The gasket ring as claimed in claim 4, wherein in its position of use itis fitted in a cylinder head, as seal between an injector and aninjector sleeve.